Brake shoe



Dec. 29; 1936.

I. N. E USTIS BRAKE SHOE Filed Nov. 7, 1952 TNVENTOR IRVING N. EUSTISATTORNEYS Patented Dec. 29, 1936 UNITED STATES PATENT OFFICE 2 Claims.(01. 188-242) This invention relates to improvements in brake shoesand/or carriers therefor and has, among its objects, to provide meansfor facilitating assembly of the brake shoes on the carrier shoe; toprovide a shoe having awheelengaging surface adapted for use on wheelsof different sizes; and-generally to provide an improved combination ofshoe and carrier.

Objects, features and advantages of the invention will be set forth inthe description of the drawing forming a part of this application, andin said drawing Figure 1 is a sectional side elevation of abrake shoeand carrier therefor constructed in accordance with the teachings ofthis invention; Figure 2 is a front face view of the carrier, viewingthat side which has the recesses;

Figure 3 is an elevation of the shoe, viewing it from the working faceside; and Figure 4 is an elevation of the shoe, viewing it from thatside which engages the carrier.

Referring to Figure 1: Numeral I indicates a wooden brake shoe carrierupon which a cast metal brake shoe or liner 2 is mounted. On that facewhich is engaged by the rear face of the shoe, the carrier has locatingrecesses 3, and on its rear face, the liner has corresponding locatingbosses 4, one for each recess and releasably fitting the correspondingrecesses.

I There are bolt holes 5 in the carrier passing therethrough and eachopens into the corresponding recess. The shoe has bolt holes I l inregister with the holes 5 of the carrier and these holes pass throughthe bosses. In this case, the bosses and recesses are cylindrical, andtheir axes are concentric with the axes of the bolt holes.

The bosses 4 and recesses lintersect the end faces of their respectiveelements so that the recesses are open at the ends. These bosses and 10recesses greatly facilitate assembly of the shoe on the carrier byobtaining a colinear registration of the bolt holes. Moreover, theyfunction to prevent assembly of the wrong shoe.

The liner has a concave wheel-engaging sur- 45 face generally indicatedl0, which may have the ordinary configuration (not shown) or a specialconfiguration, hereinafter described.

The shoe 2 has bolt-head receiving recesses I! which extend inwardlyfrom the concave 5o face Ill, and the bottoms ll of these recesses arecoplanar with-the rear face ii of the shoe which engages flatly againstthe corresponding front face I! of the carrier. Bolts ll secure theparts together, the square heads I! of H which lie in the recesses If.The depth of of the recesses is greater'than the thickness of thebolt-heads so that the heads lie well inwardly from the concave brakingsurface Ill. The bolts have suitable nuts 20, the carrier has the usualslot 2| for the reception of the 5 brake beam, and the'usual boltopening 22 traversing the carrier and slot 2|. The bolt-head receivingrecesses H are herein shown as rectangular but they may be of anypolygonal shape to correspond to the poly onal shape of 10 a bolt head,the head and recesses being shaped to cooperate or fit to preventrotation of the bolt.

A feature of this invention is the provision in a brake shoe or liner,of a concave wheel-engag us ing face comprising portions havingdiiferent radii of generation, whereby the braking surface is adaptedfor use with a plurality of sizes of wheels having tread surfaces ofcorresponding curvatures. v 20 Referring to Figure 1: The middle portion26 of the wheel-engaging face It has a radius of generation. A, centeredat B. .The terminal portions 21 at each side of the middle portion 26have a common radius of generation C, centered 25 at D. Let it besupposed that radius A is eight inches, and radius 0 ten inches. Whenthis brake shoe is used, for example with a twenty inch wheel, the outerportions 21 fit the tread and provide the required braking surface.These 30 surfaces are more or less quickly worn down so that the surfaceportion 26 eventually also participates in braking action. When the shoeis applied to the sixteen inch wheel, the center portion 26 of thebraking surface fits the tread, 35 and as wear takes place, the area ofcontact is increased until the surface portions 2! join in the brakingaction. In other words, in each case, all portions of the concave facebecome active for braking purposes. 40

An important object is to provide shoes adapted for different sizes ofwheels, but to so constmct'the shoes that they will all fit and only fita standard carrier, in a certain manner, so that replacement can only bemade with, a liner which fits the carrier. By providing sockets having aparticular configuration or arranged in a particular manner, which willregister with or, fit bosses having a corresponding configuration orarrangement, quick registration between '60 the bolt holes of the shoeand carrier can be obtained. There is, therefore, no intention to beentirely limited to the specific arrangement, lo-

cation, or configuration of the bosses and sockets. 4 l5 I claim: 1. Abrake shoe carrier element having a flat face having terminal recessestherein, a brake shoe having a flat face engaging the flat face of thecarrier and having terminal locating and reenforcing bosses fitting therecesses, the wheelface of the shoe being concave toward the flat faceand having terminal bolt head countersinking recesses opposed to thebosses, securing bolts traversing openings in the bosses and carrier andhaving heads in the countersinking recesses, the bottom surfaces of thelast named recesses being substantially coplanar with the flat face ofthe shoe, and the heads being of substantially less thickness than thedepth of the recesses so that the shoe can be worn substantially throughat its midportion before the wheel can engage the bolt heads.

2. A brake shoe having a concaved wheel- 20 engaging face and a flatopposite face, bolt head receiving recesses extending inwardly from saidconcave face, bolt holes traversing the shoe and opening into saidbolt-receiving recesses, a brake shoe carrier having a flat faceengaging the fiat face of the shoe having corresponding bolt holeopenings in register with the openings of the shoe, locating thickeningand reenforcing bosses on said shoe circumscribing the bolt holes andreleasably fitting corresponding recesses in the carrier and headedbolts in the holes securing the shoe to the carrier and having theirheads in the recesses of the shoe, the bolt head re; ceiving recessesbeing of greater depth than the thickness of the bolt heads to obtaincountersinking of the heads below the concave wheelengaging face of theshoe in a manner to permit a substantial degree of wear of said concaveface in a direction toward said flat facewithout wear of the bolt heads.

' IRVING N. EUB'IIB.

